This Program Project proposal is the most carefully organized collaborative research proposal in our history. It focuses on families in 6 culturally different, primarily low-income ethnic minority populations whose children may be at risk for mild mental retardation, developmental delay or associated maladaptive behaviors. Project 4 (Edgerton and Weisner) will pursue two related goals: (1) overall coordination of research on family adaptation in cultural context, focused on ecocultural domains of activity among the ethnic minority populations studied in other projects and (2) comparisons of the relative validity of various self-report and observational data collected in these three projects. Project 10 (Kernan, and Tucker) will alter its focus from Down Syndrome to a study of family and sociocultural "resilience" factors that protect children against educational delay and behavioral disorders in three contractive ethnic minority populations -- African-Americans, and newly immigrant Garifuna ("Black Caribs") and Creoles from Belize. Project 7 (Gallimore and Goldenberg) will extend its research on the early school lives of Hispanic children at risk for developmental and educational delay, and Project 6 (Nihira and Mink) will continue longitudinal research concerning the effects of acculturation on the home environment of Asian-American children with developmental delay.